<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>load03</title>
</head>
<body>
	<button id="btnId">SayHello</button>
</body>

<!-- 3.写到script标签中，script标签放到body标签后面，不符合我们的习惯 -->
<script type="text/javascript">

</script>
</html>